Various methods are known in the art for optical 3D mapping, i.e., generating a 3D profile of the surface of an object by processing an optical image of the object. This sort of 3D profile is also referred to as a 3D map, depth map or depth image, and 3D mapping is also referred to as depth mapping. The terms “optical” and “light,” as used in the context of the present patent application and in the claims, refer to electromagnetic radiation in any or all of the visible, infrared and ultraviolet wavelength ranges.
U.S. Patent Application Publication 2011/0279648 describes a method for constructing a 3D representation of a subject, which comprises capturing, with a camera, a 2D image of the subject. The method further comprises scanning a modulated illumination beam over the subject to illuminate, one at a time, a plurality of target regions of the subject, and measuring a modulation aspect of light from the illumination beam reflected from each of the target regions. A moving-mirror beam scanner is used to scan the illumination beam, and a photodetector is used to measure the modulation aspect. The method further comprises computing a depth aspect based on the modulation aspect measured for each of the target regions, and associating the depth aspect with a corresponding pixel of the 2D image.
U.S. Pat. No. 8,018,579 describes a three-dimensional imaging and display system in which user input is optically detected in an imaging volume by measuring the path length of an amplitude modulated scanning beam as a function of the phase shift thereof. Visual image user feedback concerning the detected user input is presented.
U.S. Pat. No. 7,952,781, whose disclosure is incorporated herein by reference, describes a method of scanning a light beam and a method of manufacturing a microelectromechanical system (MEMS), which can be incorporated in a scanning device.
U.S. Patent Application Publication 2012/0236379 describes a LADAR system that uses MEMS scanning. A scanning mirror includes a substrate that is patterned to include a mirror area, a frame around the mirror area, and a base around the frame. A set of actuators operate to rotate the mirror area about a first axis relative to the frame, and a second set of actuators rotate the frame about a second axis relative to the base. The scanning mirror can be fabricated using semiconductor processing techniques. Drivers for the scanning mirror may employ feedback loops that operate the mirror for triangular motions. Some embodiments of the scanning mirror can be used in a LADAR system for a Natural User Interface of a computing system.
The “MiniFaros” consortium, coordinated by SICK AG (Hamburg, Germany) has supported work on a new laser scanner for automotive applications. Further details are available on the minifaros.eu Web site.